The invention is directed to a gas discharge overvoltage arrestor having a housing sealed from the atmosphere space and composed of at least two electrodes and a wall of insulating material on which an ignition coating, at least one line of ignition or a surface of ignition is located. The line of ignition is essentially composed of carbon particles which are applied to the wall of the insulating material in a non-contacting fashion.
A gas discharge over-voltage arrestor is disclosed in U.S. Pat. No. 3,431,452. An ignition coating or, respectively, a line of ignition of metal, metal oxide particles or carbon particles is applied to an inside generated surface of the insulating member in a non-contacting fashion by spraying and is subsequently subjected to a heat treatment. In the known gas discharge over-voltage arrestor, however, a specific value of surface conductivity of the ignition coating, of the line of ignition or of the surface of ignition is not well defined. A range of tolerance for the variation of this value of surface conductivity is likewise not defined. As a result thereof, the risk is present in the known gas discharge over-voltage arrestor that discharge currents flowing via the line of ignition are not in a favorable range and that an overload of the line of ignition can occur, particularly given weak glow discharges. The line of ignition can thereby at least partially evaporate, whereby the response characteristic of the gas discharge over-voltage arrestor would change. Under certain conditions, therefore, the useful life of the known gas discharge over-voltage arrestor is lower than the useful life of its remaining component parts.